In some examples, body surface electrical activity (e.g., ECG signals) can be sensed by an arrangement of electrodes. The sensed signals can be processed for a variety of applications, such as for body surface mapping or electrocardiographic mapping. Since these and other processing methods can depend on body surface potential data, the quality of data for each input channel can affect the quality of the output results based on signal processing. In some types of signal processing, the signal processing can be very sensitive to anomalies in the input channels. For instance, significant noise, such as line noise or large changes in amplitude, or other variations in the input channels could produce inaccurate results as well as overshadow the important physiological information. This could render the resulting outputs computed from such input channels non-diagnostic or uninterpretable.